tty: synclink_gt: make default_params const

default_params are only read, so move them from .data to .rodata using
'const'.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230731090002.15680-7-jirislaby@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>